The present invention relates to power transistors and transcalent power devices incorporating such transistors.
The transcalent device is an operable electronic device having at least one heat pipe connected to it. Many transcalent devices which operate at high current comprise a semiconductor wafer sandwiched between two heat pipes to provide additional cooling of the semiconductor wafer. The two heat pipes are usually joined together with a structural member which protects the edge of the semiconductor device and maintains the semiconductor device under compression. The heat pipes in transcalent devices are in thermal and electrical contact with the semiconductor device. However, in order to evenly distribute the current within the body of the transistor device, the emitter is usually comprised of a plurality of heavily doped mutually interconnected emitter members in contact with the base of the transistor. The emitter members usually have a metallization layer on their exposed surface by which an external contact can be made.
Connection of a heat pipe directly to each of the individual emitter contacts has not provided good thermal and electrical contact whereby current and thermal dissipation are equally distributed among the individual emitter members. Thus, a transistor with sufficient current distribution for high current operation has not heretofore been available.